In fabricating products from continuous lengths of textile fabric, it is often necessary to cut off predetermined amounts of undesirable selvage from each of the longtudinal side edge portions of the textile fabric. This is particularly true when textile fabric is woven on air jet looms or the like which produce fringed selvages along the longitudinal side edges which are not desirable in the fabricated end products, such as bed sheets, piece goods or the like. Accordingly, such undesirable selvages must be cut off of each longitudinal side edge in predetermined widths and the cut side edges must be sealed, which is usually done by hemming or the like, to prevent raveling at the cut edges.
Apparatus has been developed for ultrasonically cutting and edge sealing thermofusible material. For the most part, such apparatus has primarily been utilized with all plastic or thermoplastic sheet materials. However, such apparatus has been proposed for cutting and edge sealing textile fabrics having at least some thermoplastic yarns therein and is advantageous for a number of reasons compared to conventional cutting and hemming operations. An example of an apparatus for this purpose is disclosed in U.S. Pat. No. 4,097,327, issued June 27, 1978. In that patent, ultrasonic cutting and edge sealing mechanisms are illustrated in FIG. 1 thereof as mounted stationary on a loom or as a separate cutting machine for on-the-loom or off-the-loom ultrasonic cutting and edge sealing. However, in either operation, if the width of the textile fabric varies or if transverse variations occur in the path of travel of the textile fabric, different widths of selvages will be removed from each longitudinal side edge portion of the textile fabric since the ultrasonic cutting and edge sealing devices are mounted stationary. The result will be that all of the undesirable selvage on each longitudinal edge of the textile fabric may not be removed with this arrangement.